Telephony.active

Non-standard
This feature is not on a current W3C standards track, but it is supported on the Firefox OS platform. Although implementations may change in the future and it is not supported widely across browsers, it is suitable for use in code dedicated to Firefox OS apps.

Summary

Returns a TelephonyCall object indicating the call that is currently active. The active call is the one that is currently receiving input from the microphone as well as tones generated by calls to the Telephony.startTone() method.